Wire retaining means for an ignition coil unit



Jan. 17, 1961 WIRE RETAINING MEANS FOR AN IGNITION COIL UNIT FlG.i

Filed Sept. 5. 1957 F|G.6 FIG] l I fd /NVENTOR RUSSELL E. PHE; 0,1/

United States fPatetO WIRE RETAINING MEANS FOR AN IGNITION COIL UNIT Russell E. Phelon, R. E. Phelon Company Inc., Longmeadow, Mass.

Filed Sept. 3, 1957, Ser. No. 681,555

6 Claims. (Cl. 336-107) lThe invention relates to an ignition coil unit and more particularly to such a unit for a magneto of the flywheel type, wherein there is a stator including a core with primary and secondary coilsl thereon and including a rotor surrounding the'stator.

An ignition coil unit has a conductor wire connected with the secondary coil thereof, and when the ignition coil unit is a part of a magneto stator said conduc or wire is adapted for connection with the spark p`ug of an en gine. The principal object of the invention is to provide improved means for engaging said conductor wire to hold it in its connected position. The invention is particularly applicable to a magneto of the ywheel type, but it is not necessarily so limited.

The drawing shows a preferred embodiment of the invention as applied to a ilywheel magneto and such embodiment will be described, but it will be understood that various changes may be made from the construction disclosed, and that the drawing and description are not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

Of the drawing:

Fig. 1 is a combined front and transverse sectional view of a portion of a magneto embodying the invention, the stator being shown in elevation and the rotor being shown in section.

Fig. 2 is a plan view of the stator.

y Fig. 3 is a side view of a portion of the stator coil unit and of the wire holding means therefor which means includes a wire retaining clip, this view being taken in the direction of the arrows 3-3 n Fig. 2.

Fig. 4 is a view similar to Fig. 3 but with the wire retaining clip omitted. V

Fig. 5 is a side view of a portion of the stator coil unit, this view being taken in the direction of the arrows 5--5 in Fig. 2.

Fig. 6 is an enlarged clip. v Y Fig. 7 is an endfview of the clip as shown in Fig. 6.

Referring to the drawing, the core of the magneto stator is shown at 10. Said core is preferably laminated and it is constructed and arranged to provide a plurality of circularly spaced poles having arcuate faces concentric with the axis of a magneto shaft 12 and equidistant therefrom. As shown, the core has three poles 14, 16 and 18, and primary and secondary coils 20 and 22 surround the intermediate pole 16. The prmary coil 20 has a relatively small number of turns, as for instance 175, and the secondary coil 22 has a relatively large number of turns, as for instance 10,000.

The primary coil 20 is suitably grounded at one end by a conductor not shown. The ungrounded end of the primary coil 20 is connected by means of an insulated conductor 24 with a suitable circuit making and breaking device, not shown, which is operated by the shaft 12. The secondary coil 22 is also grounded at one end by a conductor not shown. The secondary coil is provided at plan view of the wire retaining ICC itsungrounded end with an insulated conductor 26 by means of which it is connectible with the spark plug of an` engine.

The primary and secondary coils 20 and 22 are em- It will be understood, however, that the said positions are optional and that the invention is not so limited.

The rotor of the magneto includes a flywheel 30 which is connected with the shaft 12 so as to be rotatable therewith. The flywheel is preferably formed of nonmagnetic material and it is shown as having a disc-like outer wallcarrying an annular flange which surrounds the before-described stator. ,Located within a recess in the flange of the flywheel 30 is a permanent magnet 32 and two similar pole pieces 34, 34 which are fo-med of magnetic metal and which engage the magnet at opposite ends thereof. The inner faces of the pole pieces are arcuate and are located to move in close proximity to the outer faces of the stator poles 14, 16 and 18.

During each rotation, the magnet and the pole pieces therefor cooperate with the poles of the stator to establish a magnetic circuit in one direction through the center pole 16 and through the coils thereon and then to establish a sm'lar circuit in the opposite direction. Thus the directionof the magnetic circuit is suddenly reversed and a max'mum value of voltage is established in the primary' coil 20. The breaker mechanism is timed to break the circuit in the primary coil at approximately the instant of maximum voltage therein, thus generating a high voltageV in the secondary coil 22 which is connected with the spark plug, not shown.

p The insulating body 28 o-f the coil unit is provided at one side with a cylindrical hole 36 which is vertical and parallel with the axis of the coils. Said hole 36 is open at its lower end and is closed at its upper end, said hole being formed during the molding of the body. Ordinarily the body 28 is formed with a projecting partly cylindrical boss 38 within which said hole 36 is centrally located. A so-called tack 40 is provided which is U-shaped and has inner and outer legs 42 and 44. The tack is formed of'metal and its inner leg 42 is electrically connected with the ungrounded end of the secondary coil 22. The tack 40 is molded in place in the insulating body 28 and said tack is of such size and is so positioned that its outer leg 44 is within the hole 36 and at the center thereof. Said outer leg 44 of the tack within the hole 36 is pointed downwardly as clearly shown in Figs. 3 and 4.

The yconductor wire 26 consists of a conducting core and an outer layer of insulation, the outer diameter of the wire being such that the wire will approximately lit the hole 36. The core of the Wre 26 comprises a large number of separate conducing strands. During assembly the wire 26 is forced upwardly into the hole 36, the insulation of the wire approximately fitting the hole and the stranded core of the wire being forced onto the pointed leg 44 of the tack to effect an electrical connection. The strands of the Wire core separate to admit the point of the tack.

In order that the wire 26 may be firmly retained in position on the coil unit, a wire engaging clip 46 is provided which ts a ledge 48 on the insulating body 28.

Patented Jan. 1.7, 1961 .Y

ledge 48 is located with its bottom face flush with the bottom face of said body 28. The ledge 48 coincides in part with said boss 38 and is symmetrical therewith, but said ledge is considerably wider than the boss.

The retaining clip 46 is formed from any suitable material. It may be molded from an insulating material such as nylon or it may be formed of folded or bent sheet metal. As shown, the clip is rectangular in section and is adapted to t around the ledge 48. The clip is generally U-shaped and it has a tlat bottom wall 50 engaging the bottom face of the ledge and having inner and outer ends. The clip also has parallel upwardly extending iiat side walls 52, 52 engaging the side faces of the ledge. The clip further has coplanar top anges 54, S4 extending toward each other and engaging the upper face of the ledge at opposite sides of the boss 38. The flanges 54, 54 have parallel inner edges spaced from each other by a distance greater than the diameter of the insulation of an insulated wire to be retained. The bottom wall 50 of the clip has a slot 56 extending outwardly from the inner end of said wall. The width of the slot 56 is slightly less than the diameter of the wire insulation and the slot has a partly circular enlargement 5.8 which has a diameter somewhat greater than the width of said slot but nevertheless slightly less than the diameter of the wire insulation. The slot enlargement 58 is located to receive the wire 26 when the clip is in place on the ledge as shown. It will be observed that the inner end of the clip wall 5t) extends inwardly beyond the flanges 54, 54 and underlies tle bottom face of the main insulating body 28. The inner sides of the hole 36 and of the wire 26 are about ilush with the periphery of the rnain portion of the body 28 and the narrower portion of the slot 56 is in the inwardly projecting portion of the bottom wall 50. Y

' During assembly the wire 26 is put in place as previously described. Then the clip 46 is engaged with the ledge 48 and is forced inwardly. The relatively soft material of the wire insulation yields to permit engagement of the clip with the wire notwithstanding the fact that the wire is larger than the width of the slot 56. The walls of the clip at the periphery of the slot enlargement 58 are within an annular groove formed or pressed into the insulation of the wire 26, and thus the wire is positively retained to prevent longitudinal movement thereof out of the hole 36. The narrower inner entrance portion of the slot 56 prevents any outward movement of the clip along the ledge as the result of vibration or otherwise.

The invention claimed is:

1. The combination of an ignition coil unit comprising a primary coil and a secondary coil and a conducting tack electrically connected with the secondary coil and having a pointed end, said coil unit including a body of insulating material molded around said coils and said tack which body has a substantially vertical wire receiving hole therein which is open at the bottom and is closed at the top and into which said tack projects with the point thereof at the center of the hole and near the closed upper end thereof and extending downwardly which body also has an integral ledge adjacent the lower open end of the hole and extending transversely thereof, a conducting wire comprising a stranded central core r4 and relatively soft insulation surrounding said core, said wire being entered in and tting the hole in the body and said wire having its stranded core engaged with the pointed end of the tack, and a wire retaining clip engaged with and held by the ledge on the insulating bodyand also engaged with the insulation of the wire to prevent longitudinal movement of said wire out of said hole in said insulating body.

2. The combination as vset forth in claim l, wherein said clip is generally U-shaped with a bottom wall and with coplanar ilanges at the tops of the side walls, wherein said ledge is shaped to receive and it said U-shaped clip with said bottom wall engaging the bottom of the ledge and with said flanges engaging the top of the ledge, and wherein the bottom wall of the clip has a slot therein narrower than the diameter of the wire insulation so that said sides of said slot are within a groove pressed into said wire insulation.

3. The combination as set forth in claim 2, wherein the slot in the bottom wall of the clip has an inner entrance portion narrower than the outer portion of said slot to prevent any outward movement of the clip relatively to the wire and the ledge.

4. The combination as set forth in claim 2, wherein said body has a laterally projecting boss within which said hole is located, wherein the inner sides of said hole in said boss and of said insulated wire are substantially flush with the periphery of the main portion of the body, and wherein a portion of the bottom wall of the clip extends inwardly below the bottom of the main body and beyond said periphery of said body, the` narrower portion of said slot being in said inwardly projecting portion of said bottom Wall.

5. The combination as set forth in claim 2, wherein the hole in the insulating body is vertical and wherein said body has a laterally projecting boss within which said hole is located, and wherein said laterally projecting ledge is symmetrically located with respect to said boss but is wider than said boss.

6. For an ignition coil unit, the combination of a body of insulating material having therein a molded substantially vertical wire receiving hole which is open at the bottom and which body also has an integral ledge adjacent the open lower end of the hole and extending transversely of said hole, a conducting wire comprising a stranded central core and relatively soft insulation surrounding said core which wire is entered in and lits the hole in the body, and a Wire retaining clip engaged with and held by the ledge on the insulating body and also engaged with the insulation of the wire to prevent longitudinal movement of said wire out of said hole in said insulating body.

References Cited in the tile of this patent UNITED STATES PATENTS 1,873,122 Hartzell Aug. 23, 1932 1,883,905 Hartzell Oct. 25, 1932 1,977,122 Ehrlich Oct. 16, 1934 2,020,819 Bell Nov. l2, 1935 2,476,429 Paules July 19, 1949 2,788,502 Schelke et al Apr. 9, 1957 2,814,789 Herman et al. Nov. 26, 1957 

